Hello khawn,
The General hydroponics directions call for using 2 tsp per gallon of water for a full strength
nutrient solution. You don't want to just keep adding
nutrients to your water. When the water level drops from the plants drinking the water, you want to replace it with fresh plain water (not nutrients). Otherwise your nutrient concentrations will be out of balance. Your total water volume is important too. I wrote this article to help explain the relationship between water volume and nutrient concentrations.
What size reservoir do I need